1. Field of the Invention
This disclosure is related to antenna systems, and more specifically to Electronically Scanned Antenna (ESA) systems that can operate in multiple frequency bands.
2. Related Art
Communications systems today use plural antenna systems to communicate in multiple frequency bands. These systems often also desire the use of full-duplex operation, i.e. the ability to transmit and receive at the same time. Currently, these antenna systems use a plurality of antenna subsystems, one for frequency of operation, and one for each transmit and receive function.
As the number of frequency bands where antenna systems are operated increase, so do the number of different antenna subsystems. These antenna subsystems are high-cost, heavy, and space-consuming.
It is desirable to reduce the number of antenna subsystems by combining the functions of several subsystems into a single antenna system. Conventional ESA systems today support only half solutions, i.e. half-duplex, single frequency band operation from a single radiating aperture. Therefore, an antenna system is needed that supports multi frequency band operation in full-duplex mode of operation from a single radiating aperture.